Self-piercing die riveters have been used to join two or more materials to each other using self-piercing rivets. The materials to be joined are placed between a punch and die of the riveter. The punch contacts the self-piercing rivet at the head and drives the tail towards the die piercing the materials. The self-piercing rivet fully pierces the top sheet material(s) but typically only partially pierces the bottom sheet providing a tight joint. With the influence of the die, the tail end of the rivet flares and interlocks into the bottom sheet forming a low profile button.
Self-piercing rivets are typically fed into position on the riveter from a tape, cassette or spool for continuous production. Self-piercing rivets may be used to join a range of dissimilar materials such as steel, aluminum, plastics, composites and pre-coated or pre-painted materials. Benefits of self-piercing die riveting include low energy demands, no heat, no fumes, no sparks, no waste and very repeatable quality.
Single die riveters have replaceable dies that are slid in and out of a die receiving hole. The die receiving hole is located directly beneath the die and subsequently directly in-line with the punch motion. Having a hole in-line with the punch increases the amount of stress risers and generally requires a need to reinforce the frame of the riveter in that area. Reinforcing the frame near the die requires a larger nose of the frame which limits accessibility of the tool. As well, single die riveters do not have the flexibility to easily change out varying die shapes to allow for a single die riveter to be used with multiple die configurations.
Examples of indexing die riveters having an indexing motor located on the nose of the frame may be found in U.S. Pat. No. 6,964,094 B2 to Kondo and U.S. Pat. No. 7,810,231 B2 to Naitoh. Having indexing motors located on the nose of the frame limits the access of the tool.
The above problem(s) and other problems are addressed by this disclosure as summarized below.